Drill-hole reamer



JOSEPH ROSS, OF NEW ALBANY, INDIANA.

DRILL-HOLE BEAMER.

Application filed September 14, 1925. Serial No. 56,334.

My invention aims to provide an extremely simple and inexpensive device by means of which the inner ends of drill holes, formed in rock or coal for blasting purposes, may be enlarged, ther-eby providing each hole with a large pocket for the explosive charge, which decreases the liability of such charge blowing out of the hole and producing what is eommonlycalled a windy shot. it is estima-ted that practically ninety percent of mine fires and other disasters are caused by windy shots and by providing for their reduction, if not total elimination, I have accomplished a very desirable end.

The accompanying drawing illustrates the preferred form of the invention, the views of such drawing being briefly described as follows:

Figure 1 is a side elevation of the reamer showing the manner of inserting it into a drill hole.

Figure 2 is an enlarged edge view of the reamer.

Figure 3 is a vertical section on line 3-3 of Fig. 2.

Figure 4 is a view similar to Fig. 3 but showing the manner in which the reamer is expanded to enlarge the inner end of the drill hole.

Figure 5 is a transverse section on line of Fig. 4.

Figure 6 is a perspective view of the cuts ter expanding block.

Figure 7 is a perspective view of the tool by means of which the reainer is forced into the drill hole without expanding said reamer prematurely.

ln the drawings above briefly described,

the numeral l designates an elongated bodywhich .is closed at two opposed sides, open two other opposed sides and closed at both of its ends, said body being adapted for re ception, in its entirety, in a drill hole. One end of the body 1 is formed with an opening 2, and the inner end of a driving shank 3, passes slidably through said opening.

. The inner end of the shank is provided with a pair of pivoted reaming blades 4 which are normally confined in the body 1, but are adapted to move outwardly through the open sides of the latter when the shank is forced inwardly, after said body strikes the inner end of the drill hole, oblique cams 5 being provided in the body for outwardly forcing said blades when said shank is inwardly shifted. Thus, by rotating and inwardly lthe body 1 and the entire feeding the shank with common drill driving means or by equipping said shank with a handle and using the latter to operate it, the blades may be expandedgradually and driven to enlarge the hole, as seen in Fig. 4.

lf an attempt were made to force the reamer into the drill hole by pushing upon the shank 8, this would result in expending the blades 4, which would prevent insertion of the device. Therefore, I have provided the reamer inserting tool shown in Figs. 1 and '.7, said tool comprising a rod 6 having a forked, lateral, inner end 7- The fork is adapted to straddle the shank 3 and bear against the outer end of the body 1, so that by forcing' on said rod, the reamer may be readily inserted into the drill hole.

In the construction shown, the body 1 comprises two spaced side plates 8, and spacing blocks 9 and 10 secured between the ends thereof by rivets or other fasteners 11, the block 10 being formed with the opening 2, the latter and the inner section of the shank 3 being preferably of square cross section. The inner end of the block 9 is provided with two oblique surfaces crossing each other and forming the cams 5, each of these surfaces occupying half the thickness of the block, and the inner end of the block 10 is provided with a recess 12 normally receiving the blades 4 and serving to hold them. against outward movement. When so positioned, the free ends of the blades 4 engage the cams 5, so that as soon as inward pressure is eX- erted on the shank 3, after the body 1 comes to rest against the inner end of the drill hole, said blades will be forced outwardly. By rotating the shank 3 in any desired manner and gradually feeding it inwardly, it will be seen that the inner end of the drill hole may be readily enlarged to form the desirable receiving pocket for the blasting charge. As soon as an outward pull is exerted on the shank, the blades 4 retract into reani'er may be withdrawn from the hole.

It will be seen that by providing the construction shown and described or a substantial equivalent thereof, a very simpl-e and inexpensive, yet an efficient and desirable tool will be provided. The form of construction disclosed is preferably followed, but within the scope of the invention as claimed, numerous changes may be made.

I claim:

A drill hole reamer comprising an elongated body consisting of spaced parallel side plates and spacing blocks secured between the ends thereof,` Vone of said blocks having an opening disposed axially of the body and also having a blade-receiving recess in its inner end whereby the blades 1are held against outward movement while the rearner is being inserted in the drill vhole,tli`e inner end of the other blook being formed with opposed lblade-expanding Cams, a driving shank for the body passing slidably through the aforesaid opening, and a pair of blades pivoied the inner end of said shank and normally confined between the aforesaid side plates, the free end portions of said blades being engageable with the aforesaid cams4 when the shank is forced downwardly7 the other ends of said blades being normally seated in the above-named recess.

In testimony whereof I have hereunto 20 affixed rny signature.

Josera Ross. 

